Time-limit relay-switch.



C. RENSHAW.

TIME LIMIT RELAY SWITCH.

APPLICATION HLED MAR. 7. 1913.

1,214,074. Patented Jan. 30, 1917.

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TIME LIMIT RELAY swncn.

APPLICATION FILED MAR. 7, I913.

Patented Jan. 30, 1917.

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UNITED STATES PATENT OFFICE.

CLARENCE RENSHAW, OF EDGEWOOD PARK, PENNSYLVANIA, ASSIGNOR '10 WESTING- HOUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENN- SYLVANIA.

Specification of Letters Patent.

Patented Jan. 30, 1917.

Original application filed November 29, 1911, Serial No. 662,181. Divided and this application filed March 7, 1918. Serial 1T0. 752,618.

To all whom it may concern:

. Be it known that I, CLARENCE RnNsnAw, a citizen of the United States, and aresident of Edgewood Park, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Time-Limit Relay-Switches, of which the following is a specification, this application being a division of application Serial No. 662,181, filed November, 29, 1911.

My invention relates to time-limit relay switches such as are employed in control systems for electric motors, and particularly in connection with the automatic control of railway motors.

One of the objects of my invention is to provide a device of the above-indicated character which shall be simple, compact and durable in construction and effective and reliable in operation.

Another object of my invention is to pro vide a device which shall be particularly adapted for use in railway motor control systems through the agency of which the motors ar automatically governed during periods of acceleration.

A still further object of my invention is to provide a-relay switch of the time-element type which shall embody inexpensive and comparatively few parts that may be readily assembled and easily detached for purposes of repairs or renewals.

In my co-pending application, Serial Number 662,181, filed November 24th, 1911, of which this application is a division, I have shown and described the construction of my relay switch and have set forth its operation in a system of automatic control. Hereinafter, therefore, I shall set forth only the construction and operation of the relay switch itself, and it should be understood that modifications in structural details and in arrangement and location of parts may be made without departing from the spirit and scope of my invention.

Figure 1 of the accompanying drawings, is a view partially in elevation and partially in section, of a time-limit relay constructed and arranged in accordance with my invention, and Fig. 2 is a view, partially in elevation and partially in section, at right angles to Fig. 1, the sectional portion bemg taken on the line IIII of Fig. 1.

Referring to the drawings, the structure here shown comprises a stationary frame 1, which is adapted to be secured to the under side of the floor or deck of an electric car or locomotive, having downwardly extending projections 2, to which a supporting plate 3 of a time-limit relay switch 4 is removably attached.

The time-limit relay switch 4 comprises a cylinder 6, a piston 7 operating therein, an external U-shaped bracket 8 and a piston rod 9 which is slidably mounted in a bearing 10 provided at one end of the cylinder 6 and is interposed between the piston 7 and the bracket 8. Insulating blocks 11 and 12 are secured to the arms 11 and 11 of the U-shaped bracket 8 and are provided with projecting arms 13 and 14 through which screw-threaded rods 15 and 16 extend in lines which are substantially parallel to the line of action of the piston rod 9. Longitudinally slotted strips 17 and 18 of conducting material are secured to the lower ends of the screw-threaded rods 15 and 16 and are severally provided with movable contact members 19 and 20 at their lower ends which are respectively adapted to engage stationary contact members 21 and 22 when the piston 7 and the screw-threaded rods 15 and 16 occupy their lowest positions.

The conducting strips 17 and 18 are respectively adapted to slide over stationary contact blocks 24 and 25 to which the external connections are made and against which the strips 17 and 18 are pressed by washers 26 and small springs 27. The contact blocks 21 and 25 are mounted on stationary insulating blocks 28 from which bolts 29 extend through the slots in the strips 17 and 18, the washers 26 and the springs 27 being mounted on the outer ends of the bolts 29 and held in position by nuts 30.

The projecting arms 13 and 14 of the blocks and 12 are rovided with bushings or sleeves 31 throug which the rods 15 and 16 operate freely, and the rods 15 and 16 are provided with lock nuts 32 and 33 above said arms 13 and 14. When fluid pressure is admitted to the cylinder 6, the piston 7 is raised and carries with it the U-shaped bracket 8 and the blocks 11 and 12. Thus, the separation of the contact members 19 and 21 and 20 and 22 is accomplished successively, according to the position of the lock nuts 32 and 33 on the rods and 16, ,said lock nuts 32 and 33 being respectively engaged and lifted by arms 13 and 14. The lock nuts 33 are so adjusted that 'the contact members and 22 are separated near the beginning of the piston stroke, while the lock nuts 32 are so located that the contact members 19 and 21 are separated when 15 the piston 7 is substantially at the end of its stroke. The piston 7 is normally held in its lowest position by means of a helical spring 23 which is located inside the cylinder 6 in the usual way and is compressed when pneumatic or other fluid pressure is admitted to the cylinder 6 under the piston 7.

The admission of fluid pressure to the cylinder 6 is governed by a magnet valve 34 having a valve stem 35 which is forced downwardly in opposition to a spring 36 when either one or both of a pair of magnet coils 37 and 38 are energized. The valve is double acting and, when the electro-magnets 37 3' and 38 are de'e'nergized, closes an admission port 39 and opens an exhaust port 40, the admission port 39 being opened and the exhaust port 40 closed when said magnets are energized.

M Pneumatic or fluid pressure is supplied for operating the piston 7 through supply pipe 41, chamber 42, admission port 39 and chamber 43. The port 39 is constricted in size so that the operating fluid isadmitted at a predetermined slow rate, whereby a predetermined time interval is required to raise the piston 7 and to efi'ect the separation of the cooperating contact members 19 and 21 and 20 and 22.

M The exhaust port 40 connects the chamber 43 to a chamber 44 which communicates with the atmosphere when the valve is open to permit the spring 23 to force the piston 7 and associated movable contact members 19 and 20 to their lowest positions. A time element is provided during this operation by throttling down the escape of the operating fluid through the small exhaust port 40. It will, therefore, be understood that contact members 20 and 22 are disengaged by the initial action of the piston, whereas the separation of the contact members '19 and 21 is effected after a predetermined time interval by the final action thereof.

50 I claim as my invention:

1. In a switching device, the combination with a movable member, and a stationary member, of an arm secured to said movable member, a rod slidably mounted on said arm as and having a plurality of adjustable stops adapted to engage said arm, a contact member secured to said stationary member, a portion of said rod being flattened and biased to electrical engagement with said contact member, and a stationary member adapted to electrically engage the bottom of said rod.

2. In a switching device, the combination with a movable arm and a stationary contact member, of a rod disposed in the direction of movement of said member, a plurality of stops secured to said rod and adapted to engage said arm, a flat conducting member secured to said rod, means forbiasing said conducting member to continued electrical engagement with said contact member, and a stationary contact member that is adapted to engage the bottom of said rod for predetermined positions thereof.

3. In a switching device, the combination with power-operated means, a U-shaped supporting member associated therewith, insulating blocks secured to the respective arms of said member and having openings therein,

a plurality of conducting rods severally projecting loosely through said openings and adapted to be raised by said blocks and having flat, slotted intermediate portions, and a plurality of stationary contact members rigidly secured to said power-operated 2 means, of laterally extending members associated with said contact members and projecting through the slots in said rods, and resilient means surrounding said projecting members for maintaining good electrical engagement between said contact members and the flat portions of said rods.

4. In a switching device, the combination with relatively movable main contact members adapted for abutting engagement, a slotted member of conducting material associated with the movable contact member and means for actuating said movable contact member, of an auxiliary stationary contact member adapted to engage said slotted member, a laterally extending member rojecting through the slot in said rod, and resilient means associated with said laterally extending member for maintaining a good electrical engagement between said rod and said auxiliary stationary contact member.

5. In a switching device, the combination with a movable supporting member having an opening therein, a conducting rod loosely projecting through said opening, adjustable means associated with said rod on the opposite sides of said supporting member and 7 adapted to be engaged thereby for actuating said rod, and a movable contact member associated with one end of said rod, said rod being provided with a slotted portion having a flat working surface, of a stationary contact member adapted to cooperatively engage said flat surface, a stud projectin through the slotted portion, and a co" 0 spring surrounding the outer end of the subscribed my name this 26th day of Febstud and eating upon 1tKhe slottefd portion to ruary, 1913. maintain t e at wor ing sur ace in good electrical engagement with said stationary CLARENCE RENSHAW' 5 contact member when said movable contact Witnesses:

member and associated rod are actuated. L. S. PETER,

In testimony whereof, I have hereunto E. C. Wm'rn. 

